Conventional receivers use a passive filter preceding a low noise amplifier (LNA) to reject interference outside the frequency band of interest (with reference to prior art FIG. 1). The LNA is then used to amplify the multiple signals within the frequency band of interest. The conventional passive filters are generally large in size. Additionally, the passive filter(s) have a fixed predetermined bandwidth and out-of-band rejection. The LNA amplifies all signals and interferers within the frequency band of interest by an amplification factor that is generally relatively constant across the frequency band of interest. Thus, if an interferer is located within the frequency band of interest, it is amplified. The amplification gain and in-band interferer 108 amplification is depicted in prior art FIG. 1.
Thus, a need exists for a communication system that can adapt to varied frequency bands of interest and reduce interferers within frequency band and/or frequency bands of interest. Also, a need exists for a communications system that is reconfigurable for different frequency bands of interest.